Schlauch- oder schichtfoermiges,fluessigkeits- und gasdurchlaessiges poroeses Material und Verfahren zu seiner Herstellung

摘要

1376151 Laminated products ASAHI-DOW Ltd 20 Oct 1971 [20 Oct 1971 9 June 1971 10 June 1971] 48811/71 Headings B5A and B5N [Also in Divisions B2 and C3] A tube or sheet of fluid transmitting porous material is made by extruding a blend of (i) a low or high density polyethylene, a polypropylene, a propylene-ethylene or -hexene copolymer, a polybutene, a polypentene or an ethylenevinyl acetate -ethyl acrylate or -methyl methacrylate copolymer having less than 10% by wt. of acetate, acrylate or methacrylate groups respectively, or mixtures thereof and (ii) 5-95% by wt. of a copolymer of ethylene and vinyl acetate ethyl acrylate or methyl methacrylate having not less than 10% by wt. of acetate, acrylate or methacrylate groups respectively and the acetate copolymer having a melt index of not less than 2À0, a natural rubber, a polybutadiene rubber, a solution- or emulsionpolymerized styrene-butadiene rubber, a butadiene-acrylonitrile or -isoprene rubber, or a styrene-butadiene or -isoprene block copolymer resin: and 0À1-5À0 parts by wt./100 parts by wt. of the blend of a thermal decomposition type blowing agent. The mixture is continuously blended and thermoplasticized by the extruder to decompose the blowing agent and the mixture is extruded through a die slit with foaming under the two following extrusion conditions, where and 1À22. (as defined), and V is the extrusion speed in cm./min. In Example 8 the porous sheet is laminated, by pressure, on to a cotton cloth coated with a rubber adhesive and the laminate was then coated with a solution of nylon resin in a mixture of methanol and calcium chloride.